Was it just six months ago that much of U.S. was in the grip of a deep freeze? Through chattering teeth, Americans were hoping for the soothing warmth of the summer sun.

Now that it's here, people are feeling nostalgic for the winter.

Just three weeks into the summer, temperatures have soared up to at least 105 degrees Fahrenheit in 15 states, including Tennessee.

Folks in the Midwest, Southeast and the Plains are being advised to avoid direct exposure from the sun, with the heat index in those regions making it feel like 110 to 115 degrees.

Extreme heat warnings were also issued Monday for St. Louis, Kansas City, Memphis, Tulsa and Evansville, Indiana and of course Tennessee.

The heat wave is expected to continue through at least Tuesday and could stick around in some states until the end of the week.

Until then, cool yourself off with this thought: just 166 shopping days until Christmas.